Clips so that the rightmost point of the outPoly is at rect.x1 (e.g. a 800x600 window produces rightmost point 799, not 800). The results are suitable for pixel rendering if iRounded. Templated so that it will work for Vector2,3,4 (the z and w components are interpolated linearly). The template parameter must define T.lerp and contain x and y components.

If the entire polygon is clipped by a single side, the result will be empty. The result might also have zero area but not be empty.

True if there is non-zero area to the intersection between this and r. Note that two rectangles that are adjacent do not intersect because there is zero area to the overlap, even though one of them "contains" the corners of the other.